Differential latch mechanism



1954 K. H. TENOORT DIFFERENTIAL LATCH MECHANISM 4 Sheets-Sheet 1 Filed July 14, 1951 INVENTOR v KARL H. TENOORT HIS ATTORNEYS J 1954 K. H. TENOORT DIFFERENTIAL LATCH MECHANISM 4 Sheets-Sheet 2 Filed July 14, 1951 INVENTOR KARL H. TE NOORT HIS ATTORNEYS Jan. 19, 1954' K. H. TENOORT DIFFERENTIAL LATCH MECHANISM 4 Sheets-Sheet 3 Filed July 14, 1951 INVENTOR KARL H. TENOORT W ms ATTORNEYS 1954 K. H. TENOORT DIFFERENTIAL LATCH MECHANISM 4 Sheets-Sheet 4 Filed July 14, 1951 INVENTOR KARL H. TENOORT BY 28 ATTORNEYS Patented Jan. 19, 1954 were DIFFERENTIAL LATCH MECHANISM Karl Heinrich Tenoort, Berlin-Neukolln, germany, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Application July 14, 1951, Serial No. 236,811

Claims priority, application Germany October 21, 1950 5 Claims. 1

This invention relates to improvements in differential latch mechanism for cash registers and accounting machines and is illustrated as applied to a machine of the type shown in United States Patent No. 2,209,763, issued to Ernst reitling on July 30, 1940.

The latch mechanism provides a means for converting the lever-set machine of said Breitling patent into a key-set machine.

This invention relates to differential mechanism for cash registers and similar accounting machines of the kind in which, for each denomination of a key bank, there is provided a differential arm carrying a latch, the arm being adapted to remain coupled to a driving mechanism until the latch is tripped under the control of an operated key or a zero stop, to effect the disconnection of the arm from the driving mechanism and retain it in the set position until restoration is effected.

The object of the invention is to provide a simple and reliable form of differential latch mechanism that is economical to manufacture.

Accordingly, the invention comprises differential mechanism for a cash register or similar accounting machine including item-entering keys; a differential arm for transmitting the setting of the keys to indicating, printing, and totalizing mechanisms; a driving mechanism for the differential arm; and a latch device normally coupling the arm to a driving mechanism and arranged to uncouple the differential arm from said driving mechanism when the former has been. set under the control of an operated key or a zero stop, characterized in that the latch device includes a pair of interacting members both directly mounted on the differential arm, one of which normally locks the other in engagement with the driving mechanism, engagement of the first-mentioned member with an operated key, or zero stop, causing relative movement between the members to cause the secondmentioned member to be disconnected from the driving mechanism, and the latter member then looking the first-mentioned member in the position to which it has been adjusted under control of said operated key.

The invention will be described indetail, and, by way of example, as applied to a machine including a plurality of denominational banks of amount keys and related differential mechanisms, but, as these differential mechanisms are all identical, the description will be confined to only one of these mechanisms.

With the foregoing and incidental objects view, the invention includes certain novel features of construction and combinations of parts,

a preferred form or embodiment of which is hereinafter described with reference to the drawings which accompany and form a part of this specification.

Of said drawings,

Fig. l. is a side view taken alongside one of the banks of amount keys, showing the differential mechanism in normal or home position.

Fig. 2 shows a similar view to Fig. l, but with 7 amount key depressed, and with the differential mechanism in an intermediate operated position.

Fig. 3 shows the parts in the positions which they assume when the latch device is arrested under control of the depressed 7 key and the driving mechanism has completed its initial operating stroke.

Fig. 4 is an enlarged detail view of the latch in normal position, in respect to the difierential arm, but shows the differential arm in an operated position. r

Fig. 5 is a detail view of the zero stop in normal position.

Fig. 6 is a front elevational view showing the machine-operating mechanism. v

Fig. 7 is a side elevational view of the mechanism shown in Fig. 6.

. Detailed description The amount keys l of each amount bank are mounted on a key frame in the usual manner, and the key frame is secured on cross shafts 5 and 6, extending between side frames of the Inachine (not shown) Each key I carries a stud 2, which is guided by slots 3 in a combined guiding and aligning plate d forming part of the key frame.

A slide 1 (see particularly Figs. 2 and 3) is suitably supported for reciprocating movement by slots, such as '11, therein engaging studs 13 in the key frame, the slide 1 having, in its upper surface, a cam slot 19 for each of the studs 2, so that the said slide 1 is moved upwardly when any amount key I is depressed.

A spring 8 (Fig. 1), anchored between a stud on the slide 7 and a stud secured to the key frame, tends to maintain the slide l in the position shown in Fig. 1.

On the front lower end of the slide 1 is a lug t, which cooperates, when the parts are in home position, as in Figs. 1 and 5, with a surface it on zero stop ti, pivotally supported by a stud 52 secured to the key frame.

Fast on a shaft I5, extending across the bottom of the key banks, is a finger I4 adapted to cooperate with a stud E3 in the lower end of the zero stop l I to release depressed keys. The shaft is rocked at the end of each machine operation by a means hereinafter described.

The upper end of the zero stop II carries a stud I6, which is adapted to cooperate with a I finger !I on a latch I8 pivoted on a stud I80 on a differential arm 20 (see Figs. 2 and 3) loosely mounted on. a main shaft I50 supported in the side frames of the machine.

Also pivoted on a stud 23 on the arm 20 is a coupling pawl 22. A spring 200 (see Fig. 4) connected between a stud I9 on the latch I8 and a stud 2H on the coupling pawl 22, normally maintains a surface 24 on the latch I8 in the path of movement of a surface 25 on the coupling pawl 22. as shown in Fig. l, the clockwise movement of the latch it be ng limited by a stud 64 therein contacting the upper surface of the latch arm 20, as shown in Figs. 2 and 3.

In the home position of the parts, as shown in Fi 1. a surface 26 on the coupling pawl 22 overlies the arcuate path of a rod 21. which is common to the coupling pawl-s of all the key bank and is carried by a pair of arms 28, only one of which is shown, loose on the main shaft Iii of the machine.

The ma n shaft IE is adapted to be driven throu h one co lete clock se rev lut on at each machine operation. in a well-known manner. as il ustrated in the a ove-ment oned Brietling patent. and as hereinafter de cribed.

The arm n ha nivotallv connected thereto. at

25. one end of a link 30. the other end of which is c nn cted t a tud 3| on one end of a beam 32 loosely sup orted on a shaft 33 extending between si e frames of the machine To the other end of the be m 32 s pivoted, at 34., a pitman 35, having therein an enlar ed opening 36. which embraces a hub 260 on the main shaft I50.

he pitman 35 carries two rollers 3! and 3B, which'cooperate. respectively, with a pair of companion cams 3!! and 4 fast on the shaft I50.

Loosely mounted on the shaft 33 is an indicator setting se ment 4! of known construction. illustrated in the above Bre tling patent. which is connected at 53 by a link 42. shown best in Fig. 2, to a beam 4 pivoted on a stud 45 in the lower end of the differential arm 20. An inner arcuate surface 46 on the beam 44 is adapted to be moved into engagement with a hub 41 on the differential arm 20.

Teeth in the se ment 4! mesh with a gear 48, secured to an indicator drum I49.

Pivotally connected at 50 to the lower end of the d fferential arm 25! is a link 49, pivotally connected at to a totalizer setting segment 52, having teeth which mesh with an intermediate gear meshing. in turn, with a gear 54 secured to a totalizer wheel 55.

The forward side of the differential arm 20 carries teeth 56, which mesh with a type setting gear 5?, for setting a related type wheel (not shown) in known manner, as illustrated in the above-mentioned Breitling patent.

Fast on the main shaft I50 is a cam 58 (Fig. 2), cooperating with a roller 50 on an arm 60 fast on a shaft EiI journalled in the side frames of the machine. Also fast on the shaft 6| is another arm 62, carrying a roller 63, which is adapted to engage a rear surface of the beam 44 during each machine operation.

The main shaft I 50 is rotated by a hand crank I5I. clutched m a gear I52 on a stud I53. h

gear I52 meshes with an idler gear I54, rotatably mounted on a stud I55 on the side frame I56. The idler gear I54 meshes with a gear I51 secured to the main shaft I50. The ratio of the gears I52 to I511 is such that two complete rotations of the hand crank rotate the main shaft I50 one complete rotation.

The shaft I5 is operated when the idler gear I54I is. rotated by the hand crank I5I. The idler gear meshes with a pinion I58 rotating on a stud I59 on the side frame I56. The pinion I53 meshes with a gear I60 secured to a shaft I6I.

Secured to the side of the gear I60 is a plate I62, on which is mounted a stud I63. Also mounted on the stud I50 is a forked lever I64, bifurcated at its upper end to engage a stud I65 on an arm I66 secured to the shaft I5. A spring I61, connected to an arm I69 of the lever I64, maintains the lever I64 and the arm I66, together with the fingers I4, in normal positions, and also maintains an arm I68 of the lever I64 in the path of the stud I63.

Near the end of the machine operation, the stud I 63 engages the arm I68 and rocks the lever I64 a short distance clockwise (Fig. 7) thus tensioning spring I61. Upon clockwise movement of the lever I64, the arm I66 and consequently the shaft I5 are rocked counter-clockwise. As the stud I63 passes from engagement with the arm I68, the spring I6'I' restores the parts to normal positions, shown in the drawings.

Operation on from the path of the finger ll of the latch I8. Counter-clockwise movement of the zero stop positions a locking surface 69 thereon (see Figs. 2 and 3) under the lug 9 of the slide I, preventing return movement of the latter, so as to lock the key 7" in depressed position. The high portion of the slide between the cam slots is moved beneath the studs 2 of the unoperated keys to prevent their simultaneous depression.

The operation of the machine, either by handle or by motor, causes the main shaft I59 to rotate clockwise, as already stated, whereby the cams 39' and 40, cooperating with their related rollers 31 and. 38 on the pitman 35, move said pitman to the left, as seen in Fig. l, rocking the beam 32 clockwise, so that the link 30 rotates the driving arm 28 clockwise.

As the arm 20 rotates clockwise, the. rod 21 engages with the overlying surface 25 of the coupling pawl 22. Since the coupling pawl 22 is held against rotary movement at this time by the latch t8, the differential arm 20 is rotated clockwise by the cams 38 and 39.

. Fig. 2 shows the parts in the position just prior to the contact of the finger I! of the latch I8 with the stud 2 on the depressed key 7.

The differential arm 20 continues its clockwise movement, under the influence of the driving rod 21, until the finger I! on the latch I0 strikes the stud 2 on the depressed key '1, as shown in Fig. 3.

Further clockwise movement of the differential arm I will now cause the latch I8 to rock counterclockwise on its pivot I80, tensioning the spring 200, until the surface 24 (see Fig. 4) on said latch passes beyond the surface 25 on the coupling pawl 22, whereupon the combined pressure of the rod 2! and the spring 205 causes the coupling pawl 22 to rock counter-clockwise on its pivot 23 until an abrupt surface 65 on the pawl 22 snaps under an abrupt surface 65 on the latch I B.

The counter-clockwise movement of the latch is, when it contacts the stud 2 of the depressed key 7, causes the stud 64 to engage in a related one of a series of aligning notches 67 in the plate 4. The cooperation of the surfaces 65 and 66 causes the latch It, and therefore the differential arm 20, to be locked in adjusted position.

The counter-clockwise movement of the coupling pawl 22 removes its surface 26 from the path of the rod 2?, and the latter now continues its clockwise movement until it reaches the position shown in Fig. 3.

If the previous setting was to a lower value than the current one, the clockwise setting movement of the differential arm 28, until it has been arrested by the depressed key 7, causes the beam 44 to rock counter-clockwise on its pivot 45. The cam 58 is timed so that, after the differential arm 2! has been set under control of the depressed key 7, it cooperates with the roller 59 to rock the arms 50 and 62 counter-clockwise, whereupon the roller 63 engages the rear side of the beam 44, moving it counter-clockwise on its pivot 45, until the inner surface 46 of the beam M strikes against the hub 41 on the differential arm 20. Since the indicator segment 4| is coupled to the beam 44, it will be set to a position corresponding to the extent of travel of said beam, to set the indicator wheel Hi9, through the gear 43.

During the setting movement of the differential arm 20, the teeth 56 on its front edge, cooperating with the gear 57, set the appropriate type wheel.

If the previous setting of the differential arm 29 was to a higher value than the current setting, then, as the differential arm 20 moves clockwise, the beam 4:! will pivot clockwise about the hub 41, causing the link 42 to rock the segment 4| clockwise, to move the indicator drum I49 to the '7 position.

After the differential arm 20, the indicator wheel M9, and the type setting gear 4'! have been set, as above described, continued clockwise movement of the main shaft I50 permits the arms 5i! and 62 to be restored clockwise, by a spring (not shown), to their original positions, as the roller 59 follows the contour of the cam 58.

During the said continued movement of the main shaft I551, the cams 39 and 48 (Fig, 1) restore the pitman 35 to the right, to the position shown in this figure, the rod 2'! thereb being moved counter-clockwise. During this counterclockwise movement of the rod 27 (Fig. 3) it contacts a lower surface 68 on the coupling pawl 22, but, at this time, the latch I8 is still locked against any clockwise movement by its engagement with the stud 2. However, continued movement of the rod 21 causes the differential arm 20 to commence a counter-clockwise restoring movement, removing the latch i 8 from the restraint of the stud 2. Immediately thereafter, pressure of the rod 27 on the surface 63 of the coupling pawl 22 rocks the latter clockwise, moving the abrupt surface 55 thereon out of engagement with the abrupt surface 66 on the latch l8 and tensioning the spring 200. As soon as the said abrupt surfaces leave one another, the latch it, which, as just mentioned, is now freed from the stud 2, is rocked clockwise by the spring 205 to the position shown in Fig. 1, whereupon the surface is again interlocks with the surface 25 on the coupling pawl 22. Continued counter-clockwise movement of the rod 21 now restores the differential arm 20 to its home position, as shown in this figure.

During the restoring movement of the differential arm 20, the beam 44 pivots idly counterclockwise on the stud 43, leaving the indicator wheel I49 in the position in which it has been set.

Near the end of the cycle of machine operation, the stud 63, engaging the lever sec, rocks said lever and the arm use, to rock connection to the shaft 15 first counter-clockwise and then clockwise (Fig. 7). Upon the counter-clockwise movement of the shaft 15, the finger it is similarly moved, rocking the zero stop it clockwise to home position, removing the surface 69 (Fig. 2) thereon from the path of the lug 5 on the slide 1, releasing the latter to the action of the spring 8 (Fig. 1), which restores the slide downwardly to home position, and releasing the depressed key 7 so that it will be restored upwardl by the usual spring (not shown).

As the slide 7 moves downwardly, the lug 9 thereon is positioned in front of the surface I E) on the zero stop H. Upon the return clockwise movement of the finger M, it is removed from contact with the stud I3 in the zero stop H, whereupon the latter is rocked slightly counterclockwise by its spring until the surface iii on the zero stop I contacts the lug 9 on the slide 1, to maintain said zero pawl in its normal home position, as shown in Fig. 1.

Just prior to the clockwise movement of the rod 2'!, the intermediate gear 53 and the totalizer wheel 55 are rocked in the manner shown in the above-mentioned Breitling patent, so that the former engages with the toothed segment '52, whereby, during the clockwise movement of the differential arm 21!, the setting of the segment by the link 49 will transmit an amount corresponding to the operated amount key 5 to the totalizer wheel 55.

If none of the keys 1 has been depressed, the zero stop II will remain in the position shown in Fig. 1, so that, when the differential arm, 213 commences its clockwise movement, the stud it on the zero stop II will engage the finger I? on the latch is, causing the latter to be rocked counter-clockwise, whereupon the coupling pawl 22 will be disengaged from the driving rod 2?, the remainder of the machine operation then continuing exactly as described above, to position the indicator wheel M9, the type setting gear 51, and the totalizer wheel 55 at zero.

While the form of mechanism shown and described herein is admirably adapted to fulfill the object primarily stated, it is to be understood that it is not intended to confine the invention to the form or embodiment disclosed herein, for it is susceptible of embodiment in various other forms.

What is claimed is:

1. In a machine of the class described, the combination of a plurality of settable keys, a zero stop pawl, a differentially settable arm, a driving means for the arm, a latch member pivoted on said arm, a finger on the latch member 00* operating either with a set key or with the zero stop pawl whereby the latch member is rocked assume 7 on its pivot, a coupling member pivoted on said arm, a spring connecting the latch pawl and the coupling member, an arcuate surface on the coupling member normally engaged by the driving means, and a locking surface on the latch pawl normally held in engagement with the coupling pawl by said spring to hold the coupling member in engagement with the driving means, whereby the driving means actuates the said am,

2. In a machine of the class described, the combination of a plurality of settable keys; a zero stop pawl; a differentially settable arm; a driving means for the arm; a latch member pivoted on said arm; a finger on the latch member cooperating either with a set key or with the zero stop pawl whereby the latch member is rocked on its pivot; a coupling member pivoted on said arm; a spring connecting the latch pawl and the coupling member; an arcuate surface on the couplin member normally engaged by the driving means; a locking surface on the latch pawl normally held in engagement with the coupling pawl by said spring to hold the coupling member in engagement with the driving means, whereby the driving means actuates the said arm; a second locking surface on the latch member; a locking surface on the coupling member, said locking surface on the coupling member movable by the spring into contact with the locking surface on the latch member when the latch memher is rocked by engagement of said finger thereon with a set key or the zero stop pawl to lock the coupling member in moved position, wherein the arcuate surface is out of engagement with the driving means; a plate having a plurality of locking notches; and means on the latch member engaging a notch when in moved position to lock the latch member in a set position commensurate with the key which has been engaged by said finger.

3. In a machine of the class described, the combination of a plurality of settable keys; a zero stop pawl; a diiierentially settable arm; a driving means for the arm; a latch member pivoted on said arm; a finger on the latch member cooperating either with a set key or with the zero stop pawl whereby the latch member is rocked on its pivot; a coupling member pivoted on said arm; a spring connecting the latch pawl and the coupling member; an arcuate surface on the coupling member normally engaged by the driving means; a locking surface on the latch pawl normally held in engagement with the coupling pawl by said spring to hold the coupling member in engagement with the driving means, whereby the driving means actuates the said arm; a second locking surface on the latch member; a locking surface on the coupling member, said locking surface on the coupling member movable by the spring into contact with the locking surface on the latch member when the latch member is rocked by engagement of said finger thereon with a set key or the zero stop pawl to lock the coupling member in moved position, wherein the arcuate surface is out of engagement with the driving means; a plate having a plurality of locking notches; means on the latch member engaging a notch when in moved position to lock the latch member in a set position commensurate with the key which has been engaged by said finger; and a second arcuate surface on the coupling member engage able by the driving means when the latter is moved in return direction to rock the locking surface of the coupling member out of engagement with the locking surface on the latch member, whereupon the spring returns the latch member into position wherein the first-named locking surface of the latch member moves into po sition to maintain the coupling member in said normal position, wherein the coupling pawl is held in engagement with the driving means,

4. In a machine of the class described, the combination of a plurality of settable keys; a zero stop pawl; a differentially settable arm; a driving means; a pair of interacting members pivotally mounted on the arm, one of said members normally locking the other one of said members in engagement with the driving means; a projection on one of said members movable into engagement with an operated one of said keys or the zero stop pawl, to cause relative movement between said members and thereby to cause the other one of said members to be disconnected from the driving means and to lock the said one member in the position to which it is adjusted under control of an operated key or the zero stop, said zero stop pawl normally held in position to be engaged by said projection; a key detent movable upon depression of a key, said detent normally engaging the zero stop pawl to maintain the zero stop pawl in normal position; a locking surface on the zero stop pawl, said detent movable out of engagement with the zero stop pawl by the depression of a key to release the zero stop pawl for movement out of the path of movement of said projection, said locking surface thereupon movable into engagement with the detent to maintain the detent in moved position andthereby maintain the depressed key in depressed position; and cam slots in the detent coacting with the keys to maintain the keys in depressed position when the detent is locked in moved position by the zero stop pawl.

5. In a machine of the class described, the combination of a plurality of settable keys; a zero stop pawl; a differentially settable arm; a driving means; a pair of interacting members pivotally mounted on the arm, one of said members nor mally locking the other one of said members in engagement with the driving means; a projection on one of said members movable into engagement with an operated one of said keys or the zero stop pawl, to cause relative movement between said members and thereby to cause the other one of said members to be disconnected from the driving means and to lock the said one member in the position to which it is adjusted under control of an operated key or the zero stop, said zero stop pawl normally held in position to be engaged by said projection; a key detent movable upon depression of a key, said detent normally engaging the zero stop pawl to maintain the zero stop pawl in normal position; a locking surface on the zero stop pawl, said detent movable out of engagement with the zero stop pawl by the depression of a key to release the zero stop pawl for movement out of the path of movement of said projection, said locking surface thereupon movable into engagement with the detent to maintain the detent in moved position and thereby maintain the depressed key in depressed position; cam slots in the detent coacting with the keys to maintain the keys in depressed position when the detent is locked in moved position by the zero stop pawl; a rock shaft; a finger on the rock shaft engageable with the zero stop pawl; and means to actuate the rock shaft during each machine operation to engage the finger with the zero stop pawl to restore the zero stop 9 pawl to normal position and thereby release the Number detent and the depressed key. 2,108,476 KARL HEINRICH TENOORT. 2,176,561 2,241,987 References Cited in the file of this patent 5 2 23 03 UNITED STATES PATENTS Number Name Date Number 875,075 Heinitz Dec. 31, 190': 191,346 1,529,955 Kolbe Mar. 17, 1925 441 376 2,008,877 Robertson July 23, 1935 Name Date Dahlberg' Feb. 15, 1938 Placke Oct. 17, 1939 Eickman May 13, 1941 Robertson May 5, 1942 FOREIGN PATENTS Country Date Great Britain Jan. 4, 1923 Great Britain Jan. 27, 1936 

